The Murray Darling Depression Bioregion Murray Darling Murray Depression

CHAPTER 7 The Murray Darling Depression Bioregion Murray Darling Murray Depression

1. Location 2. Climate The Murray Darling Depression Bioregion lies in the southwest corner of NSW The Murray Darling Depression Bioregion is dominated by a hot semi-arid and extends into Vic and SA. The total area of the bioregion is 19,717,651 ha climate in the northern section of the bioregion including the northeastern with 40.71% (8,026,167 ha) of this area in NSW and covering 10.03% of the arms, and a warm semi-arid climate in the southern half of the bioregion and state. eastern outliers. Small patches in the west of the bioregion fall in the NSW arid zone (Stern et al. 2000). The NSW portion of the bioregion is bounded in the north by the Broken Hill Complex Bioregion, with the Cobar Peneplain to the northeast and the Riverina Bioregion to the east. The Murray Darling Depression Bioregion also 3. Topography borders the Darling Riverine Plains to the northwest and contains outlying remnants of the Darling River and tributaries as they meet the Murray River The Murray Darling Depression Bioregion lies in the Murray Basin on Tertiary at the Victorian border. and Quaternary sediments deposited from a shallow sea, lakes and rivers.The bioregion extends into Vic and SA. The landscape is characterised by The bioregion lies entirely in the Western Division of NSW and contains few dunefields, sandplains and undulating plains of brown calcareous soils.There town centres, with Ivanhoe, just near the tip of the Riverina Bioregion, being is very little structured drainage but numerous lakes, swamps and the major settlement aside from Manilla, Emmdale and other pastoral depressions are present, some of which are driven by saline groundwater. stations in the bioregion. The bioregion includes the Murray, Murrumbidgee, Lachlan, Darling, Barwon, Yanda River and Peacock Creek catchments.

Mean Annual Minimum Maximum Mean Annual Minimum Maximum Temperature Average Monthly Average Monthly Rainfall Average Monthly Average Monthly Temperature Temperature Rainfall Rainfall

16 – 19°C 2.9 – 4.9°C 32.4 – 35°C 210 – 408mm 12 – 29mm 22 – 40mm 80 The Bioregions of New South Wales – their biodiversity, conservation and history

4. Geology and geomorphology Lakes and depressions all have clay floors, and vegetation relates to the presence or absence of salt and gypsum. Infrequently flooded freshwater The Murray Basin is a shallow crustal depression filled with marine and lakes carry cane grass (Eragrostis australasica), lignum (Muehlenbeckia terrestrial sediments to a maximum depth of 600m over the last 50-60 cunninghamii) and nitre goosefoot (Chenopodium nitrariaceum), with clumps million years. Shallow seas have moved back and forth across the plains of black box (Eucalyptus largiflorens) on the margins. several times, leaving traces of parallel beach ridges and limestone sediments under the dunefields. At one stage the coast reached as far inland as The vegetation on lunettes varies. Clean sands often have white cypress pine, Balranald. while brown clayey sands support mallee with porcupine grass. Mixed sand and clay lunettes carry rosewood, belah, western pittosporum (Pittosporum Sandy surface sediments have been extensively reworked into dunes and phylliraeoides), narrow-leaf hopbush and bluebush. sandplains that have blown onto the Cobar Peneplain. Some dunes have consistent east-west linear patterns, others are parabolic, suggesting The largest rocky hills, Maccullochs Range, carry mulga (Acacia aneura) differences in vegetation cover, sand supply or age. The Darling River and dominated vegetation very similar to much of the Cobar Peneplain. Smaller streams in the Riverina have cut through the sands and constructed hills have more of a mixture of local sandplain species and distant rocky slope numerous overflow lakes such as the Sayers Lake system and the abandoned species. Pleistocene channels and basins of the Willandra Lakes complex. Saline groundwaters have formed salt basins in many places where the sandplain or 7.2 Significant flora dune topography intersects the water table. All lakes and swamps have well- Stipa nullanulla, now Austrostipa nullanulla, has been identified as regionally formed lunettes on their eastern margins that record evidence of climate endemic to the Murray Darling Depression Bioregion and is listed as change and human occupation. A few bedrock ridges rise above the endangered in the TSC Act 1995 (Bowen and Pressey 1993, cited in Morton et sandplains as isolated ranges. al. 1995).

Murray Darling Murray Depression Significant flora species in the bioregion include Austrostipa metatoris, 5. Geodiversity Mossgiel daisy (Brachycome papillosa), Atriplex infrequens, and Swainsona pyrophila, all listed as vulnerable in NSW. The bioregion also supports The Murray Darling Depression Bioregion has many important wetlands. irongrass (Lomandra patens), found mainly within the Cobar Peneplain Other significant geodiversity features include: Bioregion, desert carpet-weed (Glinus orygioides), found mainly in the far flooding frequency varies and water quality and lake or swamp northwest, bluebush daisy (Cratystylis conocephala), which is very rare in environments are very diverse; NSW, Olearia calcarea, found only near White Cliffs, sand cress (Pachymitus abandoned systems, such as the Willandra Lakes, preserve evidence of past cardaminoides), Indigofera helmsii and Menindee nightshade (Solanum climates and environments along with abundant archaeology; there are karsensis) (Bowen and Pressey 1993, cited in Morton et al. 1995, Cunningham many equivalent lunette sites that have not yet been examined; et al. 1981). heavy sand mineral resources and large deposits of gypsum are known but not exploited. Other significant species are the salt pipewort (Eriocaulon australasicum) and Codonocarpus pyramidalis (Fox 1991, cited in Morton et al. 1995) as well as 6. Soils Atriplex papillata near salt lakes and the yellow Darling pea (Swainsona laxa). These are considered to be relict populations and rare in NSW, although S. Soils and vegetation differ according to the landform. On the dunefields red, laxa also occurs near Menindee in the Darling Riverine Plains Bioregion brown and yellow calcareous sands occur with more clayey materials in the (Cunningham et al. 1981). swales. On sandplains the soil tends to be heavier with brown gradational or texture contrast profiles, and mallee is found only on sandy rises. Lakes and depressions all have clay floors. The more saline lakes have grey cracking clays and carry chenopods. Salt lake floors carry little vegetation. Lunettes comprise varying soils from clean sands, brown clayey sands, mixed sand to clay.

7. Biodiversity

7.1 Plant communities Typical sandplain species include rosewood (Heterodendrum oleifolium), white cypress pine (Callitris glaucophylla), narrow-leaf hopbush (Dodonea viscosa), punty bush (Cassia eremophila), belah, copperburrs (Sclerolaena sp.), black bluebush (Maireana pyramidata) and variable spear grass. The dunes support diverse mallee (Eucalyptus sp.) communities with mixed shrubs and porcupine grass (Triodia pungens). Belah (Casuarina pauper), rosewood and variable spear grass (Stipa variabilis) occupy the swales. Photo: NPWS The Murray Darling Depression Bioregion 81

Birds of the chenopod shrublands in the bioregion seem to be at risk of decline (Reid and Fleming 1992, cited in Morton et al. 1995). Most of the extant eastern mallee (Eucalyptus sp.) and its former range (now mostly wheatfields) lies in the Murray Darling Depression Bioregion. There are several large and many small mallee remnants in the bioregion.Three bird species are found mostly or entirely in the long unburnt mallee in this bioregion; the red-lored whistler (Pachycephala rufogularis), the vulnerable mallee emu-wren (Stipiturus mallee) and the endangered black-eared miner (Manorina melanotis). Major populations of the endangered eastern subspecies of regent parrot (Polytelis anthopeplus), which moves between mallee and river red gum vegetation, are found in the bioregion. The western whipbird (Psophodes nigrogularis), the vulnerable malleefowl (Leipoa ocellata) and the endangered plains wanderer (Pedionomus torquatus), the range of which is centred on the Riverina, can also be found. More than 4% of birds observed in the bioregion are exotic species, including the Eurasian skylark (Alauda arvensis), European goldfinch (Carduelis carduelis) and the common starling (Sturnus vulgaris), all of which have adapted well to the agricultural landscapes of the bioregion. Numbers of the musk lorikeet (Glossopsitta concinna) have increased in the

bioregion, as have temperate forest and temperate woodland birds. Darling Murray Depression

Photo: G. Bridle Conversely, grassland, ground-nesting birds and ground-feeding insectivorous species have decreased in numbers. The general trend in this 7.3 Significant fauna bioregion is a gradual decline in numbers in isolated habitat fragments, and extinctions that occur in major mallee blocks during rare, large-scale fires.The The malleefowl (Leipoa ocellata), which is listed as endangered in the TSC Act, future of many bird populations in the bioregion may be dependent on is found throughout western NSW, including in the Murray Darling appropriate fire management as well as the restoration, expansion and Depression Bioregion (Priddel 1990, Garnett 1992, cited in Morton et al. 1995). linking of habitat fragments. The plains-wanderer (Pedionomus torquatus), listed as vulnerable in the TSC Act, is found in this bioregion as well as in the Riverina Bioregion (Baker-Gabb The skink (Ctenotus brachyonyx) inhabits spinifex grasslands in the Murray et al. 1990, Garnett 1992). Darling Depression and Simpson-Strzelecki Dunefields bioregions in NSW and also occurs in Qld. Populations of the elapid snake (Notechis scutatus) are Black-eared miners (Manorina melanotis) are listed as endangered in both declining in riverine habitats along the Murray-Darling system, while the state and Commonwealth legislation, as they are at great risk of extinction python (Morelia spilota variegata) also appears to be declining in several and, within NSW, are now found only in the Murray Darling Depression vegetation types (Sadlier and Pressey 1994, cited in Morton et al. 1995). The Bioregion (Garnett 1992, cited in Morton et al. 1995). The preferred habitat of distribution of the southern bell frog (Litoria raniformis) seems to be the black-eared miner is dense, undisturbed old-growth mallee, which has retracting from its northwestern limit (Sadlier and Pressey 1994, cited in undergone widespread clearing in NSW since the arrival of European settlers. Morton et al. 1995). This has resulted in the species occupying more open habitat, which is the preference of the yellow-throated miner (Manorina flavigula).This in turn has 7.4 Significant wetlands promoted cross-breeding between the two species, reducing the occurrence of pure forms of the black-eared miner (NSW NPWS 1999a). The Darling Anabranch Lakes provide large areas of habitat for waterbirds when inundated (ANCA 1996). The lakes are considered to be in a fair The endangered eastern subspecies of the regent parrot (Polytelis condition, although they are declining due to changed hydrology caused by anthopeplus ssp. anthopeplus) is generally confined to areas where mallee salinity, water abstraction and regulation, weir construction upstream, occurs adjacent to riverine woodlands in both the Murray Darling Depression construction of levee banks and lake bed cropping. and Riverina bioregions (NSW NPWS 1999b). With an estimated NSW population of about 500 individuals, the species is considered to be at risk The Lowbidgee Floodplain has also been described as degraded although it due to loss of potential nesting trees with the clearing of river red gum provides an important refuge when other wetlands are dry, and it supports (Eucalyptus camaldulensis) and mallee communities (NSW NPWS 1999b, breeding colonies of Australian white ibis (Threskiornis molucca), glossy ibis Morton et al. 1995). Bush thick-knees (Burhinus grallarius) are also considered (Plegadis facinellus), straw necked ibis (Threskiornis spinicollis), royal spoonbill to be at risk in the bioregion (Morton et al. 1995). (Platalea regia), great egret (Casmerdius albus) and intermediate egret (Egretta intermedia) (ANCA 1996). Although known to occur across most of NSW, the freckled duck (Stictonetta naevosa) is recorded as breeding in the wetlands of the Great Cumbung Conoble Lake is a significant wetland of the bioregion, and is predicted to be Swamp and Lowbidgee Floodplain in the Murray Darling Depression able to support 11,000 waterbirds. There have been many sightings of the Bioregion and other nearby bioregions (Morton et al. 1995). Many waterbirds vulnerable Major Mitchell’s cockatoo (Cacatua leadbeateri) near Conoble Lake, in the bioregion and species such as the azure kingfisher (Alcedo azurea) are while two endangered plants, Kippistia suaedifolia and Dysphania reported to be of conservation concern because of changes in their habitats plantaginella, have also been recorded. (Morton et al. 1995). 82 The Bioregions of New South Wales – their biodiversity, conservation and history

Lake Victoria supports the endangered southern bell frog (Litoria raniformis), 9. Bioregional-scale conservation the vulnerable Major Mitchells Cockatoo and the endangered regent parrot (Australian Terrestrial Biodiversity Assessment 2002), as well as providing Conservation management in the Murray Darling Depression Bioregion is habitat for 20,000 waterbirds (Kingsford et al. 1997). achieved through a range of conservation mechanisms that together occupy about 421,082 ha or 5.25% of the bioregion. The Willandra Creek and Lakes is one of the most significant wetland areas in the bioregion, supporting a variety of threatened species even though it has Mechanisms provided for under the NPW Act 1974, and specifically national been described as being in a degraded condition and declining (Australian parks and nature reserves, are responsible for the majority of land conserved. Terrestrial Biodiversity Assessment 2002). Many sightings have been recorded Mallee Cliffs and Mungo National Parks (NPW Act 1974) both lie wholly within here including the blue-billed duck (Oxyura australis), freckled duck the bioregion. Eight nature reserves occur either partially or wholly within the (Stictonetta naevosa), black-breasted buzzard (Hamirostra melanosternon), bioregion and together with the national parks occupy 279,343 ha or 3.48% of Australasian bittern (Botaurus poiciloptilus), Major Mitchells cockatoo, the bioregion. None of the reserves in the bioregion is also managed as painted honeyeater (Grantiella picta), barking owl (Ninox connivens), little wilderness areas under the Wilderness Act 1987, although the Willandra Lakes pied bat (Chalinolobus picatus), inland forest bat (Vespadelus baverstocki), Region is included on the globally recognised World Heritage list as one of stripe-faced dunnart (Sminthopsis macroura), long-haired rat (Rattus three world heritage areas in NSW. Occupying approximately 240,000 ha or villosissimus), slender darling pea (Swainsona murrayana) and mossgiel daisy almost 3% of the bioregion, the Willandra Lakes region is protected by (Brachyscome papillosa). Endangered species found at Willandra Creek include international convention as well as by the Commonwealth EPBC Act 1999, the southern bell frog (Litoria raniformis), Australian bustard (Ardeotis which automatically protects all Australian properties that are on the World australis) and plains wanderer (Pedionomus torquatus) (Australian Terrestrial Heritage List. About 10% of the Willandra Lakes Region World Heritage area is Biodiversity Assessment 2002). in Mungo National Park, which covers about two-thirds of Lake Mungo. Despite its name, the world heritage area is not within Willandra National Two other wetlands, which provide significant habitat for waterbirds but are Park in the Riverina Bioregion. Murray Darling Murray Depression currently described as being in a degraded condition are Gunnaramby Swamp and Moornanya Lake. There are no Aboriginal areas, no historic sites, no state recreation areas and no regional parks in the bioregion. No voluntary conservation agreements or Gol Gol Lake (Benanee) lies partly in the Murray Darling Depression Bioregion property agreements have been entered into with landholders, although 9 but occurs mostly within the Riverina. Nettlegoe Lake and Poopelloe Lake fall wildlife refuges are held by landholders and occupy about 1.76% of the partly in the bioregion but mainly in the Darling Riverine Plains Bioregion. bioregion. Threats to wetlands in the Murray Darling Depression Bioregion include feral A small proportion (0.07%) of the bioregion is managed as State forests for a animals, exotic weeds, salinity, water abstraction and regulation, and range of forestry practices under the Forestry Act 1916, including timber regulation producing perennial flooding (National Biodiversity Audit). production and forest management. There are 10 State Forests managed primarily for forestry activities and one flora reserve (Peacock Creek Flora 8. Regional history Reserve) which occupies 0.001% of the bioregion and spans the border with the Riverina Bioregion. 8.1 Aboriginal occupation For information on the Aboriginal occupation of the Murray Darling Depression Bioregion, refer to Chapter 1 under the heading "Regional history".

8.2 European occupation Ivanhoe, the main town of the Murray Darling Depression Bioregion, was established after the first land was sold at the town in 1869. In 1870, Cobb and Co Coaches opened routes through Ivanhoe, and the town continued to develop, first with a general store and then with a post office. Police were present in Ivanhoe from 1879 to protect the public from the local Hatfield Bushrangers and by 1885 the mounted police had arrived. This same year the Ivanhoe Jockey Club held its first race meeting. The first bank opened in 1926 and the railway reached Ivanhoe in 1927, an important addition to the town as water could now be carried from nearby lakes from where it had previously been carted by dray.The pubs of Ivanhoe were an important part of the town, bringing visitors to stop in the town on their way. As in other bush towns, the development of bush pubs occurred along the route of the mail coaches, and their need for watering points – both for themselves and their horses. The main land use around Ivanhoe in the 1870s was sheep and stations such as Kilfera, which employed close to 200 people at shearing time when 8,000 sheep per day were shorn.The station carried up to 200,000 merino sheep on its 832,000 acres. Photo: NPWS The Murray Darling Depression Bioregion 83

10. Subregions of the Murray-Darling Depression Bioregion (Morgan and Terrey 1992)

Subregion Geology Characteristic landforms Typical soils Vegetation

South Olary Plain Quaternary aeolian Dunefields, sandplains, Deep siliceous and Diverse mallee on sands with; pointed sands and lake dry lakes and calcareous red to yellow mallee, congoo mallee, red mallee, lerp sediments. groundwater basins. sands, sandy earths, mallee, slender-leaf mallee, yorrell, white brown texture contrast cypress pine, mallee cypress pine, belah, soils on dunes and rosewood, with porcupine grass and sandplains. Saline, diverse shrubs. Belah, rosewood, black gypseous and bluebush, pearl bluebush, old man calcareous clays on lake saltbush, on sandplains and heavier soils. beds, mixed sands and Black box fringing depressions, halophytes pelleted clays in on salinas, and chenopod shrublands on lunettes. lunettes, sometimes with white cypress pine.

Darling Depression Quaternary aeolian Extensive sandplains. Deep siliceous and Belah, rosewood, nelia, mulga wilga and sands and lake Dunefields piled against calcareous red to yellow woody shrubs on western sandplains. Murray Darling Murray Depression sediments. Isolated Cobar Peneplain ranges. sands, sandy earths, Pointed mallee, congoo mallee, yorrell Devonian quartz freshwater overflow brown texture contrast with diverse shrubs and porcupine grass, sandstone outcrops. lakes fed by rare floods soils on dunes and occasional kurrajong and mallee cypress in the Darling River. sandplains. Brown and pine on eastern sandplains. Mulga, white Stony ridges and grey and calcareous cypress pine, red box, mallee, belah and ranges. clays on lakes. Pale poplar box on central dunes. Lignum, yellow sands on canegrass, black bluebush and black box lunettes. Stony loams or poplar box on margins and beds of on hills. swamps and lakes. Mulga with red box and shrubs on rocky hills. 84 The Bioregions of New South Wales – their biodiversity, conservation and history

11. References Australian Terrestrial Biodiversity Assessment 2002. National Land and Water Resources Audit, Canberra. Australian Nature Conservation Agency (ANCA) 1996. A Directory of Important Wetlands. Canberra. Baker-Gabb, D.J. Benshemesh, J.S. and Maher, P.N. 1990. A revision of the distribution, status and management of the Plains-wanderer, Pedionomus torquatus. The Emu 90:3. Bowen, P. and Pressey, R. 1993. Localities and habitats of plants with restricted distributions in the Western Division of New South Wales, NSW National Parks and Wildlife Service, Hurstville. Cunningham, G., Mulham,W., Milthorpe, P.and Leigh, J. 1981. Plants of western New South Wales. NSW Government Printer, Sydney. Fox, M.D. 1991. The natural vegetation of the Ana Branch – Mildura 1:250,000 map sheet (New South Wales). Cunninghamia 2: 443-493. Garnett, S. 1992. The action plan for Australian Birds. Australian National Parks and Wildlife Service, Canberra. Murray Darling Murray Depression Kingsford, R.T., Tully, S. and Davis, S.T. 1997. Aerial surveys of wetland birds in eastern Australia – October 1994 and 1995. NSW National Parks and Wildlife Service, Hurstville. Morgan, G. and Terrey, J. 1992. Nature conservation in western New South Wales. National Parks Association, Sydney. Morton, S.R., Short, J. and Barker, R.D. with an Appendix by Griffin, G.F. and Pearce, G. 1995. Refugia for biological diversity in Arid and Semi-arid Australia. A report to the Biodiversity Unit of the Department of Environment, Sport and Territories. CSIRO Australia, Canberra. NSW NPWS 1999a. Threatened Species Information: Black-eared Miner. NSW National Parks and Wildlife Service, Hurstville. NSW NPWS 1999b. Threatened Species Information: Regent Parrot. NSW National Parks and Wildlife Service, Hurstville. Priddel, D. 1990. Conservation of the mallee fowl in New South Wales – an experimental management strategy in Noble, J.C. et al. (eds) The Mallee Lands – a conservation perspective. CSIRO, Melbourne. Reid, J. and Fleming, M. 1992.The conservation status of birds in arid Australia, Rangeland Journal 14:65-91. Sadlier, R.A. and Pressey, R.L. 1994. Reptiles and amphibians of particular conservation concern in the western division of New South Wales: a preliminary review. Biological Conservation. 69: 41-54. Stern H., de Hoedt G. and Ernst J. 2000. Objective Classification of Australian Climates. Bureau of Meteorology, Melbourne.

Website http://www.outbacknsw.org.au/ivanhoe.htm